The stars were out in full fashion force on the 91st Academy Awards red carpet.
Celebrities let their outfits do the talking in every colour under the rainbow.
Here are the looks that lit up social media.
And the best dressed goes to....
Actor Billy Porter, who has won both a Tony and a Grammy for his role in Kinky Boots, stunned the red carpet in a custom tuxedo-gown.
When you come to the Oscars, you must dress up. Thanks @CSiriano for creating this custom couture masterpiece. @OscarHeymanBros you have outdone yourselves with your iconic jewels. Style by @sammyratelle Grooming by Anna Bernabe. @TheAcademy #AcademyAwards2019 #oscars #oscars2019 pic.twitter.com/IpTG2OK20x— Billy Porter (@theebillyporter) February 24, 2019
The star of US drama TV series Pose told Vogue he's "always been inspired by fashion" and that his outfits are all about coming to terms with his gay identity.
Jada Pinkett Smith was also a big fan of the look and thanked Billy for "saving Black History Month".
Fashion fans have been raving about his Christian Siriano dress, for its perfect mix of the masculine and feminine.
Just think: you have the honor of living on the same planet at the same time as Billy Porter.#Oscars2019— Charlotte Clymer🏳️🌈 (@cmclymer) February 24, 2019
Billy Porter has been a blessing to us every single day of his life. What fortune to be living beside someone who shines so magnificently. https://t.co/EZqKGTWyck— Saeed Jones (@theferocity) February 24, 2019
It costs how much?
Did you recognise the diamond in Lady Gaga's necklace when she stepped onto the red carpet?
The rock, known as the Tiffany Diamond, was worn by Audrey Hepburn in 1961 (in a different setting) for promotional shots for Breakfast at Tiffany's.
Jewellery giant Tiffany said it had released the gem - reported to be worth as much as $50 million (£38 million) - from its vault "specifically for Lady Gaga".
First discovered in South Africa in 1877, the 128.54-carat yellow diamond is thought to be one of the biggest in the world.
Gaga teamed the jewel with diamond earrings, elbow-length gloves and a black strapless Alexander McQueen gown with structured hips and a fishtail hem.
Selma Blair inspires at Vanity Fair's party
Selma Blair made her first public appearance since announcing she had been diagnosed with multiple sclerosis.
She attended the Vanity Fair Oscars party in a dress, cape and walking stick.
Many people commented on her bravery and how her story could inspire others who may also have the condition.
This makes me cry. I have a friend whose Dad has MS. It’s just incredible the strength people have to get up everyday. Amazing will & spirit.— Whitney of WorthyStyle (@worthystyle) February 25, 2019
Is it a bird? Is it a plane? No, it's a bunch of celebrities wearing some pretty cool caped gowns.
Glenn Close, nominated for best actress for The Wife, wore a stunning gold lamé cape dress on the red carpet.
Melissa McCarthy, who was nominated for best actress for Can You Ever Forgive Me?, also jumped on the cape vibe in a black and white ensemble.
It seems that Killing Eve's favourite assassin has a few celebrity fans, judging by some of the looks on the red carpet.
Jodie Comer better look out, as she could have some rivals to contend with when season two comes around.
it looks like the dress code for tonight's oscars is villanelle pic.twitter.com/WedYzm7B6r— ellie (@eleanorbate) February 24, 2019
Everyone wants to be Villanelle and I am not complaining. pic.twitter.com/tBjSshhqsU— jake jortles (@yarnheaux) February 25, 2019
American actress Linda Cardellini wore fuchsia taffeta on the red carpet. She stars in Green Book and A Simple Favour.
Crazy Rich Asians' Awkwafina served some serious looks in her glittery lilac tuxe by Dsquared 2.
US singer Kacey Musgraves also looked pretty in baby pink - her dress is from the Giambattista Valli spring 2019 collection.
Red carpet rainbow
While last year's awards season was dominated by sombre colours as celebrities came out to support the #MeToo and Time's Up movements, 2019's Oscars were full of every colour of the rainbow.
Dame Helen Mirren led the fashion pack in a vibrant Schiaparelli gown, complete with multi-toned pink chiffon and some seriously sparkling jewels.
Emma Stone and Rachel Weisz, who were both nominated for best supporting actress for The Favourite, fully embraced colour on the Oscars red carpet.
Emma wore a brown and gold Louis Vuitton dress, while Rachel rocked a red floral vinyl dress.
New hair, new me?
Charlize Theron got the internet talking when she rocked the red carpet in a powder blue Dior gown and a brunette bob.
i have to say charlize theron is the eighth wonder of the world pic.twitter.com/6fjQxTTP8X— ً (@arrivhal) February 25, 2019
All hail Queen Melissa McCarthy
Melissa McCarthy presented the award for best costume in perhaps the most show-stealing look yet, a Tudor frock covered in fluffy (toy) rabbits.
This paid homage to Olivia Colman's portrayal of Queen Anne's pet rabbits in The Favourite.
McCarthy's skit with Brian Tyree Henry, who looked equally fetching, set social media alight.
Melissa McCarthy.— andy lassner (@andylassner) February 25, 2019
The #Oscars producers just aggressively played off actual Oscar winners and cut their mics so we could spend more time looking at Melissa McCarthy with a bunny puppet, in a punchline costume covered with stuffed bunnies to mock THE FAVOURITE. pic.twitter.com/Bef688CZ9a— Tasha Robinson (@TashaRobinson) February 25, 2019